The goal for this series is to introduce the hmm_range_fault() output array flags HMM_PFN_PMD and HMM_PFN_PUD. This allows a device driver to know that a given 4K PFN is actually mapped by the CPU using either a PMD sized or PUD sized CPU page table entry and therefore the device driver can safely map system memory using larger device MMU PTEs. The series is based on 5.8.0-rc3 and is intended for Jason Gunthorpe's hmm tree. These were originally part of a larger series: https://lore.kernel.org/linux-mm/20200619215649.32297-1-rcampbell@xxxxxxxxxx/ Changes in v2: Make the hmm_range_fault() API changes into a separate series and add two output flags for PMD/PUD instead of a single compund page flag as suggested by Jason Gunthorpe. Make the nouveau page table changes a separate patch as suggested by Ben Skeggs. Only add support for 2MB nouveau mappings initially since changing the 1:1 CPU/GPU page table size assumptions requires a bigger set of changes. Rebase to 5.8.0-rc3. Ralph Campbell (5): nouveau/hmm: fault one page at a time mm/hmm: add output flags for PMD/PUD page mapping nouveau: fix mapping 2MB sysmem pages nouveau/hmm: support mapping large sysmem pages hmm: add tests for HMM_PFN_PMD flag drivers/gpu/drm/nouveau/nouveau_svm.c | 238 ++++++++---------- drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmm.c | 5 +- .../drm/nouveau/nvkm/subdev/mmu/vmmgp100.c | 82 ++++++ include/linux/hmm.h | 11 +- lib/test_hmm.c | 4 + lib/test_hmm_uapi.h | 4 + mm/hmm.c | 13 +- tools/testing/selftests/vm/hmm-tests.c | 76 ++++++ 8 files changed, 290 insertions(+), 143 deletions(-) -- 2.20.1
